<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="https://unpkg.com/element-ui/lib/theme-chalk/index.css">

</head>
<body>
<el-radio-group v-model="isCollapse" style="margin-bottom: 20px;">
    <el-radio-button :label="false">展开</el-radio-button>
    <el-radio-button :label="true">收起</el-radio-button>
</el-radio-group>
<el-menu default-active="1-4-1" class="el-menu-vertical-demo" @open="handleOpen" @close="handleClose" :collapse="isCollapse">
    <el-submenu index="1">
        <template slot="title">
            <i class="el-icon-location"></i>
            <span slot="title">导航一</span>
        </template>
        <el-menu-item-group>
            <span slot="title">分组一</span>
            <el-menu-item index="1-1">选项1</el-menu-item>
            <el-menu-item index="1-2">选项2</el-menu-item>
        </el-menu-item-group>
        <el-menu-item-group title="分组2">
            <el-menu-item index="1-3">选项3</el-menu-item>
        </el-menu-item-group>
        <el-submenu index="1-4">
            <span slot="title">选项4</span>
            <el-menu-item index="1-4-1">选项1</el-menu-item>
        </el-submenu>
    </el-submenu>
    <el-menu-item index="2">
        <i class="el-icon-menu"></i>
        <span slot="title">导航二</span>
    </el-menu-item>
    <el-menu-item index="3" disabled>
        <i class="el-icon-document"></i>
        <span slot="title">导航三</span>
    </el-menu-item>
    <el-menu-item index="4">
        <i class="el-icon-setting"></i>
        <span slot="title">导航四</span>
    </el-menu-item>
</el-menu>


</body>

<style>

    .el-menu-vertical-demo:not(.el-menu--collapse) {
        width: 200px;
        min-height: 400px;
    }

    .el-menu-vertical-demo:not(.el-menu--collapse) {
        width: 200px;
        min-height: 400px;
    }
</style>

<script src="https://unpkg.com/element-ui/lib/index.js">
    export default {
        data() {
            return {
                isCollapse: true
            };
        },
        methods: {
            handleOpen(key, keyPath) {
                console.log(key, keyPath);
            },
            handleClose(key, keyPath) {
                console.log(key, keyPath);
            }
        }
    }
</script>
</html>